A wide variety of Analog to Digital Converters (ADC) is available for different applications at varied sampling rates and resolutions, including both synchronous and asynchronous ADCs. Synchronous ADC are driven by a global clock and sample the signal at regular intervals, while Asynchronous ADC are clockless. Asynchronous ADC (AADC) can be sub-categorized in two categories: asynchronous logic type and asynchronous analog type. In the asynchronous logic type ADC, the input is sampled at regular intervals. But, the time to convert the input analog quantity into digital quantity is generally asynchronous. In the asynchronous analog type of ADC, the input is not sampled; rather the continuous time input is compared continuously with a reference quantity. In this type of ADC, the Input-Output (I/O) can be truly asynchronous, although the asynchronous output can be further re-timed so that digital interface is synchronous.